| abstract |
(57) [Problem] To prevent a Si wafer from containing a unique defect such as FPD, COP, and OSF. A surface layer (12) of a first substrate (11) is separated from another second layer (12). In the bonded base material formed by being transferred onto the surface of the base body, a base body including at least a Si base body manufactured by a floating zone method as the first base body 11 is prepared. A step of bonding the base 11 to the second base 15, a step of separating the bonded base by an ion implantation layer 14 previously formed on the Si base of the first base of the base, Removing the ion-implanted layer 14 exposed on the surface on the substrate side. |